Nice use of the palette, the shadows & lighting could fall better, BUT, I really like this painted style..there is no need for correction if the viewer of this piece expands his mind a little bit (like all the artists here should) and realizes that not everything has to have perfect symmetry, and sober straight line work.
And see the good thing about the "painted feel" to this image. You can play off the fact that the knight is dead or "fallen". To let people realize that at first glance, you might want to make a picture frame around the knight 4 or 5 pixels wide, with a cool little pattern or something.
Want to give some dough back to all those amazing pixel artists? Donations provide prize money for contests, help cover hosting costs and support new initiatives.
:O Nice use of colours, the crack in the helmet is just bothering me for some reason, though. xD
Otherwise, it's really beautiful!